The removal of H.sub.2 S from a liquid or gaseous hydrocarbon stream is a problem that has long challenged workers in many industries. For example, one such area is in the petroleum industry where the H.sub.2 S content of certain crudes recovered from oil field reservoirs in many areas of the world is too high for commercial acceptance. The same is true for recovered natural gas streams. The presence of H.sub.2 S presents many environmental and safety hazards in that it is highly flammable, is toxic by inhalation, and is a strong irritant to eyes and mucous membranes. In addition, the presence of such sulfur-containing compounds may result in the deposition of sulfur-containing salts which can cause plugging and corrosion of transmission pipes, valves, regulators and the like. Even if the natural gas is flared as a waste stream from petroleum production, it is necessary that the H.sub.2 S either be completely removed or at least reduced to a level where the combustion products from the flaring do not introduce deleterious amounts of pollutants such as, for example sulfur dioxide, So.sub.2, a component of "acid rain."
Since H.sub.2 S has an offensive odor and natural gas containing it is often called "sour" gas, treatments to reduce or remove H.sub.2 S are often termed "sweetening". When a particular compound or agent is used to remove or reduce H.sub.2 S levels, the agent is sometimes referred to as a scavenging agent. The sweetening or removal of H.sub.2 S from petroleum or natural gas is only one example of where H.sub.2 S level reduction or removal must be performed. In the manufactured gas industry or the coke-making industry, coal gas containing unacceptable amounts of H.sub.2 S is commonly produced by the destructive distillation of bituminous coal having high sulfur content. Another H.sub.2 S contamination problem is found in the manufacture of water gas or synthesis gas where it is not unusual to produce gas streams containing H.sub.2 S by passing steam over a bed of incandescent coke or coal containing a minor amount of sulfur. H.sub.2 S removal is also a frequently encountered problem in the petroleum industry because the principal raw material, crude oil, typically contains minor amounts of sulfur--principally in the form of organic sulfur compounds. During the course of the many processes to which the crude oil or fractions thereof are subjected, one or more gas streams containing H.sub.2 S often result.
Regardless of the source of the liquid or gas stream, the problem of removing or reducing H.sub.2 S levels therefrom has been solved in numerous different ways in the past which generally involve one or more of the following techniques: selective absorption with a wide variety of absorbents; absorption by suitable absorbent; and selective reaction with a reagent which produces a readily separable product. The details of these techniques are known to those skilled in the art. Indeed, a number of systems using amines, aldehydes, alcohols, and reaction products of these materials are known. The voluminous number of prior art processes, patents and publications concerning the removal of H.sub.2 S from liquid and gas streams testifies to the facts that (a) the desirability and necessity of removing the H.sub.2 S from the streams, and (b) that up to now no completely desirable process has been found. There remains a continuing need for improved processes and compounds to reduce and/or remove the presence of H.sub.2 S in liquid and gaseous hydrocarbon streams.